PROJECT SUMMARY/ABSTRACT In May 2016, the Food and Drug Administration (FDA) issued a Final Rule, bringing electronic nicotine delivery systems (ENDS) and other products that meet a statutory definition of a tobacco product under its authority. Federal law explicitly prohibits five categories of labelling and advertising for tobacco products including: (1) false and/or misleading; (2) FDA-approved or FDA-endorsed, without FDA approval; and (3) modified risk tobacco product, without FDA approval. Additionally, ENDS cannot be marketed as a product for (4) smoking cessation or for (5) other therapeutic purposes, without prior approval from the FDA's Center for Drug Evaluation and Research (CDER). Although these types of ENDS claims have been documented online and in print media, it can be difficult to identify prohibited claims as they are often implicit. The FDA has been tasked with considering consumer perceptions of such claims when determining if they are prohibited; however, there is a significant gap in the literature regarding consumer perceptions of health claims. Additionally, no research has been conducted on advertising claims made in vape shops, which are the fastest growing segment of ENDS retailers. This study will build upon a pilot grant that developed the methodology to photographically document ENDS claims in vape shops using wearable imaging technology. In the proposed study, we will use this methodology to conduct an additional wave of data collection to document claims in vape shops. The claims from both the pilot and the new wave of data collection will be combined to create a comprehensive list of unsubstantiated claims for use in a survey, which will investigate consumer perceptions of them. It will be the first of its kind to assess how consumers interpret these real-world ENDS health claims made by retailers. At the conclusion of this study, we will have developed robust methodologies for capturing claims in the ENDS retail environment; expanded the knowledge of the types of ENDS claims being made to consumers; and developed measures for assessing consumer perceptions of those claims, all of which will aid the FDA in making determinations of whether such claims fall into one of their prohibited categories. This focused project, led by a New Investigator working with a nationally recognized team of collaborators, will lay the groundwork for future, larger studies that will increase the body of evidence regarding ENDS and directly inform the process in which the FDA identifies and classifies prohibited advertising claims.